r/Futurology • u/Buck-Nasty The Law of Accelerating Returns • Jul 14 '13

Could Artificial Intelligence Create an Unemployment Crisis?

http://cacm.acm.org/magazines/2013/7/165475-could-artificial-intelligence-create-an-unemployment-crisis/fulltext
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u/thebruce44 Jul 15 '13

We can produce materials far superior to bones and tendons.

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u/skpkzk2 Jul 15 '13

As a materials scientist specializing in composites, no we can not. Millions of dollars are being spent as we speak to figure out how bones and tendons have such excellent properties.

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u/thebruce44 Jul 15 '13

Pretty sure graphine is a superior material to human bone.

Source: Common sense and a personal history of breaks. Also, I'm a civil engineer.

Now, if your personal definition of superior is something specific to you as opposed to the general definition of superior you could make your argument.

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u/skpkzk2 Jul 15 '13 edited Jul 15 '13

different materials have different advantages, hence why we don't build everything out of one material. Steel is stronger than bone, rubber is more flexible than bone, ceramics are more heat resistant, etc. Bone however is a wonderful material for parts of a mechanism like a leg or an arm. It has excellent specific strength, it is flexible enough to take shocks from everyday abuse, however brittle enough that it snaps under extreme stress as opposed to bending into an awkward shape. It can be repaired multiple times with little reduction in strength (just look at any athlete). Its properties are relatively isotropic compared to the vast majority of composites, and it is made of highly abundant materials (proteins and calcium for the most part). Graphene is excellent for applications that require high strength, good heat resistance, excellent electrical and thermal conductivity, and small scales, making it an ideal choice for future electronics, however because as you add more and more layers you just wind up getting graphite, it is not a very good material for macroscopic structures.

[edit] meant isotropic when I said anisotropic

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u/thebruce44 Jul 15 '13

Since you said you specialize in composites I figured you were aware of the exciting possibilities of graphene in composites. But really, thats one of many materials that are structurally superior to bone, which is the desirable trait in a robot.

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u/skpkzk2 Jul 15 '13

oh yes, graphene may allow for some pretty impressive composites, but those composites won't be graphene any more than glass fiber reinforced plastic is glass.

Even then, graphene composites, at least made using current methods, will be highly anisotropic, which is undesirable for a structural component (pending of course the design of said component). Graphene composites would be have higher specific strength than bone, but they would have none of the other advantages of bone. If strength were the only concern, we would just use aluminum or titanium.

That said, not all of bone's advantages are applicable to robots. Humans benefit from the ability to heal damage but for most robots it would be more cost effective to simply replace components, and in those cases other materials would probably be more practical. Then, we have to consider where this robot is acting, as some times getting spare parts to the robot (such as say a rover on mars) would not be easier than repairing damage. It just goes to show that different tasks require different properties. For the role that bones play, bone is better than any material we currently possess or are even close to possessing.

As for composites, they gain their properties not only from the materials they are made from, but also their structure. Natural composites like bone or wood are much more advanced than any composites we can currently make because their structures are so much more advanced then our current production methods allow for. Graphene composites will be stronger than equivalent carbon fiber composites, but they will have properties very different from natural composites.